Public defence in Processing of materials, M.Sc. Aydin Bordbar Khiabani

Title of the thesis: Evaluation of in vitro degradation and associated risks of novel biomaterials for implants

Doctoral student: M.Sc. Aydin Bordbar Khiabani
Opponent: Professor Gabriela Graziani, The Polytechnic University of Milan, Italy
Custos: Professor Michael Gasik, Aalto University School of Chemical Engineering, Department of Chemical and Metallurgical Engineering

Performances of novel biomaterials in simulated biological conditions

The thesis explores innovative approaches to enhance the performance of orthopaedic metallic alloys by addressing the electrochemical behavior related to simulated post-implantation inflammatory conditions. The work comprises a detailed comparison between commercial purity titanium (Ti Group 2 alloy), Ti–6Al–4V alloy (Group 23) and novel Ti–Nb–Zr–Si (TNZS) alloy. Electrochemical studies conducted in various media, mimicking normal, inflammatory, and severe inflammatory conditions. The major media differences were mimicked by varying concentration of H2O2, albumin, and lactate. The outcomes indicate i.a. a superior corrosion resistance of TNZS attributed to the presence of silicide phases. In addition, for Group 2 and Group 23 alloys this work examines the electrochemical behavior of additively manufactured (3D printed) patterned titanium layers made of titanium powder of the same composition. For this case, the results reveal an improved corrosion resistance in 3D patterned specimens compared to untreated titanium alloys surfaces.
For analysis of more innovative methods of the improvement of the corrosion behavior of metallic alloys tantalum coated with Mn3O4 nanoparticles and 3D patterned titanium with alginate hydrogels laden with octacalcium phosphate (OCaP) particles were studies in these simulated inflammatory media. It was observed that electrophoretic deposition of Mn3O4 nanoparticles on anodized tantalum demonstrates superior corrosion protection for implants in inflammatory conditions, and potential corrosion protection mechanism has been suggested, highlighting nanoparticles’ catalytic activity and sealing role, offering valuable insights for developing corrosion-resistant implant materials. For hydrogel-coated titanium alloys, improved hydrophilicity and OCaP phase crystallinity were observed and an effective reduction of corrosion current density has been found, emphasizing the potential of such coatings to mitigate inflammatory-associated corrosion.

Thesis available for public display 10 days prior to the defence 
Contact information:
M.Sc. Aydin Bordbar Khiabani
[email protected] 

Doctoral theses in the School of Chemical Engineering
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